Beware of claims such as the one you say that Amsoil makes--that its 2-stroke oil can be used at 100:1 regardless of what ratio the engine manufacturer recommends. If Amsoil did say this, some engine manufacturers are probably going nuts right about now. I understand the need to try to stick to one ratio when you have different 2-strokes around that use different ratios, but going with such a low ratio simply because the oil manufacturer says to is playing with fire. New engines are far more expensive than oil.
Back in the late 1970s, a certain well-known synthetic oil (not Amsoil) claimed you could go 12,000 miles between oil changes using its product in motor vehicles. Of course, no car manufacturer then, and few today, were saying that if you used this specific oil, you could extend oil change intervals. None of the carmakers then differentiated between regular and synthetic oils in maintenance specs, and this oil became notorious for causing seals and gaskets to leak badly. The 100:1 claim reminds me of this fiasco, which did much to hurt synthetics here in the US. Beware.